The Calvin cycle, or light-independent reactions, uses the ATP and NADPH produced during the light-dependent stage to convert inorganic carbon dioxide into organic sugar molecules. This process occurs in the stroma of the chloroplast. The key enzyme, RuBisCO, catalyzes the first step: the fixation of [latex]CO_2[/latex] into an organic molecule, initiating a cycle that produces carbohydrates.
The Calvin Cycle (Carbon Fixation)
- Melvin Calvin
- Andrew Benson
- James Bassham
The Calvin cycle proceeds in three main stages. The first is carbon fixation, where the enzyme RuBisCO attaches a molecule of CO2 to a five-carbon sugar, ribulose-1,5-bisphosphate (RuBP). This creates an unstable six-carbon intermediate that immediately splits into two molecules of a three-carbon compound, 3-phosphoglycerate (3-PGA).
The second stage is reduction. Using energy from ATP and reducing power from NADPH (both supplied by the light reactions), the 3-PGA molecules are converted into a three-carbon sugar, glyceraldehyde-3-phosphate (G3P). This is an energy-intensive step that effectively stores the light energy in chemical bonds.
The third stage is regeneration. For every six molecules of G3P produced, one exits the cycle to be used by the plant to synthesize glucose and other organic molecules. The other five G3P molecules, along with more ATP, are used to regenerate the three molecules of RuBP that began the cycle. This ensures the process is sustainable, ready to fix more CO2.
Taper
Perturbation
Usage
Précurseurs
- discovery of radioactive carbon-14 by martin kamen and sam ruben, which was used as a tracer
- development of paper chromatography by archer martin and richard synge
- understanding of ATP and NADPH from the light-dependent reactions
- f.f. blackman’s law of limiting factors, suggesting a two-stage process
Applications
- genetic engineering of crops to improve RuBisCO efficiency
- understanding the global carbon cycle
- developing strategies to increase crop yields
- modeling plant responses to elevated atmospheric CO2
Brevets:
Idées d'innovations potentielles
!niveaux !!! Adhésion obligatoire
Vous devez être membre de l'association pour accéder à ce contenu.
DISPONIBLE POUR DE NOUVEAUX DÉFIS
Ingénieur mécanique, chef de projet, ingénierie des procédés ou R&D
Disponible pour un nouveau défi dans un court délai.
Contactez-moi sur LinkedIn
Intégration électronique métal-plastique, Conception à coût réduit, BPF, Ergonomie, Appareils et consommables de volume moyen à élevé, Production allégée, Secteurs réglementés, CE et FDA, CAO, Solidworks, Lean Sigma Black Belt, ISO 13485 médical
Nous recherchons un nouveau sponsor
Votre entreprise ou institution est dans le domaine de la technique, de la science ou de la recherche ?
> envoyez-nous un message <
Recevez tous les nouveaux articles
Gratuit, pas de spam, email non distribué ni revendu
ou vous pouvez obtenir votre adhésion complète - gratuitement - pour accéder à tout le contenu restreint >ici<
Inventions, innovations et principes techniques connexes